ToplineShares of Warner Bros. Discovery slid Friday to their lowest level ever, even after the HBO and CNN parent’s streaming unit became the first major streamer aside from Netflix to record a profitable year on record, exemplifying the struggles of legacy media companies to return shareholder value in the era of streaming.Warner Bros. Discovery CEO David Zaslav Getty Images for Warner Bros. Discovery Key FactsWarner Bros. Discovery’s stock fell 10% to about $8.60 by late afternoon, storming toward its low ...